1. Technical Field
Various embodiments of the present invention relate to electronic devices. More specifically, the exemplary embodiments of the present invention relate to memory strings and a semiconductor device including the same.
2. Related Art
A non-volatile memory device is a memory device capable of retaining data stored therein even when power cut-off occurs, and it may include memory strings as a cell array for storing data. Here, each of the memory strings includes a drain selection transistor, a plurality of memory cells, and a source selection transistor that are connected in series. Each of the memory strings is connected to a source line via the source selection transistor, and connected to a bit line via the drain selection transistor.
The memory strings are arranged on a substrate in a horizontal or vertical direction. In the related art, memory strings are arranged on a substrate in the horizontal direction by forming memory cells in a single layer. However, a method of arranging memory strings on a substrate in the vertical direction by stacking memory cells has been suggested.
However, memory strings having the structure described above are limited in increasing cell current. Furthermore, when memory strings are arranged in the vertical direction, the properties of a memory device may be degraded due to interferences between memory cells adjacent in x/y/z-axis direction, respectively.